Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1978 Subaru GF Automatic TransFACTORY OEM SERVICE PROCEDURE
Subaru Models
- Connect a voltmeter and leads to battery as shown in Fig 1. Operate the alternator and turn off the switch "SW" when alternator speed reaches approximately 800 RPM. Increase speed in small increments while watching voltmeter deflection and read alternator speed when at 14 volts. Speed should be approximately 1000 RPM.
- Make test connections using a 30-50 ampere variable resistor, battery, ammeter, and voltmeter as shown in Figure. Operate alternator with switch "SW-1" closed. When alternator speed reaches approximately 800 RPM, set the variable resistor to maximum and turn on switch "SW-2". Increase alternator speed while maintaining a constant 14 volts by adjusting resistance. Read current at 2500 RPM and 5000 RPM. Readings should be 37-43 amperes at 2500 RPM and 48-54 at 5000 RPM.
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.